2023 GMC Sierra 1500 AT4X Review: Gentle Giant

GMC’s pricey flagship off-roader has less power and clearance than the 450-horsepower Raptor, but it does get a nicer interior.

Verdict

8.9 / 10

Design | Comfort | Tech | Performance | Safety | Fuel Economy | Pricing | FAQ

Hot off a much-needed facelift last year, the 2023 GMC Sierra 1500 lineup will try to maintain that freshened momentum thanks to a tougher, more capable AT4X variant. Although it looks similar to the existing AT4 trim level, the AT4X brings a totally new suspension with Multimatic DSSV shocks to the table, among other off-road refinements.

Mechanically, the Sierra AT4X shares a lot with the likewise-new Chevrolet Silverado 1500 ZR2, but the two trucks offer slightly different exterior and interior designs. Befitting its status as a GMC, the Sierra is also intended to be a bit more luxurious, almost like an off-road–ready Denali pickup. The upmarket positioning has a downside, however, with the AT4X starting at almost $83,595, which is more than the ZR2 and nearly as much as the Hellcat-powered Ram 1500 TRX. Still, the Sierra 1500’s off-road capability and cabin comfort make a tantalizing blend that might be worth the cash.

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Gallery: 2023 GMC Sierra 1500 AT4X Review

Design

9/10

• Exterior Color: Summit White
• Interior Color: Obsidian Rush
• Wheel Size: 18 Inches

The 2023 AT4X has all the same cosmetic enhancements as the 2022 Sierra 1500, which received revised front styling and a totally updated interior as part of a mid-cycle facelift. The exterior is about as attractive as ever.

The only downside is the roller-skate fitment of the 32-inch tires, compared to 33s on the Chevrolet Silverado 1500 ZR2 – a new front bumper treatment with more clearance will make space for bigger tires on the 2024 model (or there’s an available AEV editino that really goes bonkers). The Sierra AT4X is still a handsome machine thanks to its trim-specific red tow hooks and monochromatic styling details that swap in body-color and gloss black styling elements instead of chrome.

Inside, the Sierra is vastly improved relative to its pre-facelift predecessor, vaulting the truck from the back of its class to near the front. The sharper, more angular dash design and segment-competitive interior materials give the Sierra a modern cabin appearance that’s vastly better than the monolithic design of the pre-facelift pickup. The literal and figurative centerpiece of the design is a slick 13.4-inch touchscreen – more on that later.

Comfort

8/10

• Seating Capacity: 5
• Seating Configuration: 2 / 3
• Cargo Capacity: 62.9 Cubic Feet

There’s an impressive amount of space in the Sierra 1500 AT4X, with rear seat room that even rivals full-size luxury cars. The front seats are flat and have barely any lateral support, but I found them to be supportive enough for hours-long stints without complaint – some of my colleagues disagree, finding them to be too hard for true long-distance comfort.

At least there’s standard heating, ventilation, and massage up front and heat in the rear, to go along with a smooth freeway ride and excellent noise insulation, in spite of the mud-terrain tires at all four corners. The smallish center bin and nonexistent open console storage some unfortunate shortcomings in this otherwise nice cabin – other full-size trucks make use of that space between the front seats a lot better.

Like its Chevy Silverado corporate cousin, the Sierra has a deep, wide cargo box that gives it almost as much space in short-bed form as its competitors have in their medium-size beds. There are also a variety of tie-downs back there, and the AT4X comes standard with GMC’s novel MultiPro tailgate, which can be configured into a convenient bed step, flip-up load stop, desk surface, and more.

Technology & Connectivity

9/10

• Center Display: 13.3-Inch Touchscreen
• Instrument Cluster Display: 12.3 Inches
• Wireless Apple CarPlay or Android Auto: Yes

With no shortage of digital real estate in the cabin, the 2023 Sierra 1500 is massively improved over its technologically challenged predecessor. All trims except the base Pro get a 13.3-inch center touchscreen, 12.3-inch digital instrument cluster, and wireless Apple CarPlay and Android Auto standard. (Oddly, the Pro trim makes do with the old Sierra’s interior layout and design.)

With built-in Google Maps and Assistant, the infotainment system’s learning curve is very short for anyone who knows how to use a smartphone, and touch response is very good whether you’re tapping on-screen icons or pinching and panning the map. The wide layout of the center touchscreen is also easier to use than the Ram’s vertical 12.0-inch display.

Performance & Handling

8/10

• Engine: 6.2-Liter V8
• Output: 420 Horsepower / 460 Pound-Feet
• Transmission: 10-Speed Automatic

The naturally aspirated 6.2-liter V8 under Sierra 1500 AT4X’s hood might appear a little dated compared to the downsized, turbocharged, and hybridized powertrains found elsewhere in the full-size truck segment. But its 420 horsepower and 460 pound-feet of torque are perfectly matched to the 10-speed automatic transmission, making the GMC feel plenty powerful when launching off the line. The mellifluous baritone rumble coming from the tailpipes is an added boon – no synthesized engine noise or vacuum-cleaner exhaust note here. Alternatively, a diesel comes standard on the AT4X starting in 2024.

The AT4X’s trick Multimatic DSSV shock absorbers are shared with the Silverado 1500 ZR2, and they feature internal spool valves instead of damping shims and pistons to control wheel motions. The spool valves open and close depending on fluid pressure and motion inside the shocks, all without any driver intervention, allowing the truck to handle a wider variety of terrain than traditional monotube shocks. The net result is an excellent ride on the road without sacrificing body control on rough surfaces, and the AT4X even handles pretty decently – though you’ll get plenty of howl from the tires as cornering speeds rise.

Safety

9/10

• Driver Assistance Level: SAE Level 2 (Hands On)
• NHTSA Rating: Five Stars
• IIHS Rating: Not Ranked

Every GMC Sierra 1500 comes standard with automatic emergency braking and lane-departure prevention, while the AT4X trim also gets adaptive cruise control and blind spot monitoring with trailer coverage. GM’s excellent Super Cruise hands-free driver assistance is only available on the Sierra Denali and Denali Ultimate, though.

Still, the AT4X does just fine at keeping the truck centered in the lanes and a safe distance from surrounding traffic, with decently smooth application of the throttle, brakes, and steering.

Fuel Economy

3/10

• City: 14 MPG
• Highway: 17 MPG
• Combined: 15 MPG

Pricing

1/10

• Base Price: $77,500 + $1,795 Destination
• Trim Base Price: $79,295
• As-Tested Price: $80,440

The $79,295 starting price of the GMC Sierra 1500 AT4X puts it in some pretty tough competition, costing more than the Baja-ready Ford F-150 Raptor and nearly as much as the Hellcat-powered Ram 1500 TRX. The Sierra AT4X’s narrow-body, trail-friendly layout is more competitive with the mechanically identical Silverado ZR2 and the twin-turbo, hybrid Toyota Tundra TRD Pro, both of which are a few grand cheaper than the AT4. And then there are the Ram 1500 Rebel and Ford F-150 Tremor, which admittedly don’t feature the same trick suspension tech as the AT4X but are around $20,000 less expensive to start.

However, none of the competitors listed above feature nearly as much standard equipment as the 2023 GMC Sierra AT4X. Optioned similarly, the price disparity shrinks a whole lot, even discounting the microfiber suede headliner and front seat massagers that are standard in the Sierra and unavailable in the competition. Although some would call those additions frivolous in an off-road pickup, they do help underscore GMC’s intentions with the AT4 and AT4X sub-brand: Denali-level luxury in a rugged package.

Silverado 1500 AT4X Competitor Reviews:

• Ford F-150 Tremor: Not Rated
• Chevrolet Silverado 1500 ZR2: 9.0/10
• Ram 1500 Rebel: Not Rated
• Toyota Tundra TRD Pro: Not Rated 

FAQs:

What Is The GMC Sierra 1500 AT4X?

The GMC Sierra 1500 AT4X is the off-road flagship of the GMC half-ton lineup. With better ground clearance and wheel travel than lesser Sierras, it features Multimatic DSSV shock absorbers for better performance in taxing off-road situations.

What’s The Difference Between the Sierra AT4 And The Sierra AT4X?

The regular Sierra AT4 has a lifted suspension, like the AT4X, but the AT4X makes use of advanced DSSV shocks instead of traditional monotube shocks. The DSSV dampers perform better when internal temperatures rise, and they handle a variety of off-road situations well, ranging from high-speed desert running to mountain trails and rock crawling. The AT4X also gets front and rear locking differentials, as well as a longer list of standard equipment including heated, ventilated, and massaging front seats.

What size tires does the GMC Sierra 1500 AT4X have?

The 2023 GMC Sierra 1500 AT4X has Goodyear Territory mud-terrain tires in a LT275/65R18 size, translating to roughly 32 inches in diameter. The 2024 model, however, will get LT275/70R18 tires, which are about 33 inches tall.

Keyword: 2023 GMC Sierra 1500 AT4X Review: Gentle Giant